Method of and apparatus for constructing tanks and the like



O 12, 1943. J. M. CRQM, 2,331, 57

METHOD OF AND APPARATUS FOR CONSTRUCTING TANKS AND THE LIKE Filed April14, 1942 2 Sheets-Sheet l clizza l 62 0222 a?) r v y %%3 22%8' Oct.- 12,1943. J. M. CROM 2,331,657

METHOD OF AND APPARATUS FOR CONSTRUGTING TANKS AND THE-LIKE Filed April14, 1942 ZSheets-Sheet 2 v aw zzzom vention.

Patented Oct. 12, 1943 UNITED STATES PATENT OFFICE METHOD OF ANDAPPARATUS FOR CON- STRUCTING TANKS AND THE LIKE John M. Crom,Washington, D. 0.

Application April 14, 1942, Serial No. 438,918

9 Claims.

This invention relates to. method of and apparatus for constructingtanks and the like, and more particularly concerns the formation ofcurved or circular concrete walls in sections about a common center.Such walls and tanks are commonly constructed as monoliths and requirethe erection of extensive circular forms, staging, etc. The primaryobject of my invention is the production of a novel method and apparatusfor building such construction in sections and in a manner eliminatingextensive forms, staging, etc. and the large expense incident theretofor material andlabor.

My invention contemplates the employment of segmental form supportsmounted for movement to different positions about a common and centrallydisposed axis and adapted to support concrete receiving form surfacesfacing outwardly from the axis, these surfaces being in a common circleabout the axis and providing forms for sectional parts of the wall orstructure to be constructed. Desired steel reinforcement can be erectedin place adjacent to the form surfaces and cementitious composition isthen projected onto the surfaces to the desired depth. After the formedwall has set, the form support is moved to another position and anothersection of the wall is formed in like manner on a form -supportedthereby, the employment of a plurality of form supports permitting theshooting of one section while the previously shot section is setting.The operation is repeatedly continued until the desired wall or likeconstruction is completed.

Walls,'tanks and the like are usually of substantial height andordinarily require the erection of extensive scafiold ingto accommodatethe workmen and equipment. Another important feature of the inventionrelates to novel means in the form of a circular track disposed aroundthe proposed wall location and adjacent to the forms and carrying one ormore cars with scaffolding extending to the height of the forms.

This scaffolding provides convenient support for the workmen adjacent tothe forms and the cars can be conveniently moved to accommodate thedifferent form locations. The production of such improved and convenientapparatus which eliminates the extensive scaffolding heretofore requiredcomprises a further object of the in- Other features of the inventionrelate to a novel dome-ring form on and cooperating with the main formfor the production of tank walls together with a dome-ring thereon, andto means permitting the retraction of the dome-ring and main form fromthe set walls when it is desired to move the forms to a difierentlocation wherein Fig. 4 is a side elevation of the dome-ring form,

- Fig. 5 is a fragmentary front elevation thereof, Fig. 6 is a frontelevation of the cars and scaffolding employed, and

' Fig. 7 is a fragmentary plan view of the centrally disposed pivotaxis.

One primary use for my invention resides in the construction ofpneumatically placed concrete tanks and especially such tanks coveredwith a pneumatically placed concrete dome supported at its periphery ona dome-ring, and in the accompanying drawings I have illustrated myinvention in connection with the construction of such a tank. Theapparatus which I employ is relatively simple and inexpensive and isadapted to be used repeatedly without substantial deterioration, theapparatus illustrated incorporating a form-supporting frame 10 and aform l4 constructed as a permanent part of the frame and movabletherewith.

In Fig. 1 I have illustrated three segmental frames I0 anchored at theirinner ends on a common vertical axis l2 and having at their outer endsoutwardly facing form surfaces H in a common circle l5 disposed aboutthe axis, the frames being relatively adjustable to different positionsabout the axis. The axis I2 is disposed at the center of the tank to beformed and the circle [5 is disposed at the inner cylindrical surface ofthe proposed tank. The frames can be of any desired construction, eachframe illustrated comprising a segmental unit having horizontal membersl6 converging to the axis [2 and connected at H and frame work l8supporting a form having an outwardly facing surface M. The form is of aheight corresponding to the height of the proposed tank and is supportedat M3 by bracing 20 extending rearwardly from an elevated position onthe form and engaging the cross piece IT. The inner ends of the membersl6 are connected to plates l9 slotted at 2| to receive the axis pin l2.The segmental frame ll) serves to support the forms in the severalarcuate positions about the axis l2 whereby eliminating the necessityfor the extensive framework heretofore required, it being understoodthat the forms can be a permanent part of the frame and movabletherewith to new positions after the wall projected thereonto has set.

The bottom 22 of the tank is first constructed and a vertical anchoringaxis pin 12 is set therein at the central axis of the proposed tank,although it will be apparent that the invention can be practiced withoutemploying such pin or any centrally disposed anchor. The inner ends ofthe frames are anchored for rotation on and about this pin and theframes can be provided with casters 24 for facilitating their movementon the base 22. When the frames are adjusted to the desired workingpositions they are blocked up at 26 to an elevation raising the castersoff the base.

Each frame l has mounted on top horizontal surface 28 a dome-ring form30 having a downwardly and outwardly facing contour illustrated in thedrawings as comprising surfaces 34 and 36 at the bottoms and front sidesof steplike elements 32, and an upwardly facing surface is provided onthe frame at 28 (Fig. 4). The form 30 is braced at 38 and is slidableradially on the platform 28. In Figs. 2 and 4 the dome-ring form isillustrated as located in proper position for forming the dome-ring onthe top of and in conjunction with the wall formed on the surface M. Thedome ring is not required for open tanks having no cover.

The relatively tall forms l0 require scaffolding support for the workmenand the production of a movable and semi-permanent structure for thispurpose comprises a further feature of the invention. To this end, Iprovide a track or rails 40 extending circumferentially around andadjacent to the circle 15. One or more cars 42 on this track areprovided with scaffolding having platforms 44 at different convenientworking elevations. Preferably I provide two or more cars and bridge thegaps therebetween at the platform levels with planking 46. The cars canbe moved along the track by hand or by a small engine 48. In inclementweather the workmen are protected by a canvas or like covering 50secured to the frame l0 and draped over posts 52 and downwardly of thecar scaffolding It will be understood that one or any desired number ofform segments can be employed in constructing a tank and the tanksections can be constructed in such arrangement and sequence as seemsmost convenient. In Fig. l I have illustrated two relatively adjacentsegments 54 of the tank wall as having been formed on two of the formsurfaces l4, and a third form together with the scaffolding cars arelocated at a relatively spaced position 56 preparatory to constructinganother segment of the tank. While subsequently formed segments arebeing constructed, the previously formed segment or segments are settingand the frames from the latter can be moved to new positions and used tosupport forms for forming further segments as the setting thereof iscompleted, such operations being continued until the entire tank wall iscompleted.

In locating and preparing the form for use, it is swung about the center12 to the desired location and then blocked up at 26, and the domeringform 30 is moved outwardly to and secured in the position of Figs. 2 and4. Reinforcement rods 58 are placed vertically and in spaced relationfrom the form a distance approximating the thickness of the proposedwall, and mesh 60 is secured in contact with and inwardly of the rods.The bottom ends of the rods are preferably formed into anchoring hooks62 and the top ends are uniformly curved inwardly at 64 and secured tothe top of the dome form at 66. The cementitious composition isprojected onto the form, through the reinforcement and mesh, to athickness enclosing the reinforcement and is screeded by contact ofscreed boards with the other surfaces of the rods. The dome-ring isformed by filling the entire form space within the reinforcement andmesh as shown in Fig. 2.

After the formed wall and dome-ring have set, the segment is moved toanother position as follows. The dome-ring form 30 is first released andmoved inwardly sufficiently to clear the stepped surfaces 34 and 36 fromthe concrete, as illustrated in broken lines in Fig. 2. The blocks 26are then removed and the form dropped onto the casters 24. Along withthis latter movement, the entire form frame II] is given a slight radialadjustment inwardly, the frames being provided with the slots 2| at thepin l2 to permit such adjustment. The frame is then free for movement onthe casters 24 to the next position of use.

The reinforcement rods are tapped with a hammer sufficiently to loosentheir bonding engagement with the concrete and when the entire tank walland dome-ring have been completed and are fully set the reinforcement isplaced under tension. This tensioning is effected by rotating the sleevenuts 10 which operation also places the wall in compression. The hookedends 62 serve to anchor the rods at their bottom ends and the top endscan be suitably anchored in the dome-ring by shooting cementitiouscomposition into bonding engagement with such ends. I also prefer tobond in the bottom ends of the rods, as illustrated at 12, beforetensioning the rods. The tank is thereafter completed by placing rodreinforcement under tension circumferentially around the tank in contactwith the vertical rods 58 and then projecting on and into bondingengagement with both such rods a suitable layer of concrete, all asdescribed in my Patent No. 2,315,894 dated April 6, 1943.

Having thus described my invention what I claim as new and desire tosecure by letters Patent of the United States is:

l. A method of constructing a curved tank wall and dome-ring in sectionsdisposed about a common center, which consists in providing a formhaving an outwardly facing convex surface curved about a predeterminedcenter and a domering form at the top thereof having a downwardly andoutwardly facing contour, forming a concrete wall section on saidsurfaces, shifting the form downwardly and inwardly toward the centersufficiently to clear the formed wall section after the concrete hasset, moving the form about said center to an adjacent position andforming another cementitious wall section thereon, and continuing theoperation of thus forming cementitious wall and dome-ring sections aboutthe center until the desired wall and dome-ring is completed.

2. Apparatus for constructing a concrete tank wall and dome-ring insections disposed about a common center, comprising a main form having aconcrete-receiving surface facing outwardly from a predeterminedcenter,-a dome-ring form on the top of the main form and having a formcontour facing downwardly and outwardly, the dome-ring form beingadjustable radially inward relative to the main form to clear saidcontour from contact with a concrete dome-ring formed thereon, and meansanchoring the forms for movement about said center to differentpositions in which the said surface is disposed substantially within anare extending about said center.

3. Apparatus for constructing a cylindrical concrete Wall in sections,comprising a plurality of segmental frames anchored at their inner endson a common vertical axis and having, at their outer ends outwardlyfacing surfaces in a common cylindrical plane disposed about the axis,the frames being relatively adjustable to different positions about theaxis and said surfaces being adapted to receive wall-formingcementitious composition projected thereonto pneumatically from pointsspaced outwardly therefrom.

4. A method of constructing curved concrete walls, tanks and the like,on a base and in sections disposed about a common center, which consistsin supporting a form having a surface extending upwardly from the baseto the height of the wall to be formed and curved arcuately about andfacing outwardly from a vertical axis at said center, projectingcementitious composition pneumatically against said surface from pointsspaced outwardly therefrom and to a" depth forming a cementitious wallthereon, thereafter moving the form support about said axis to anadjacent position and forming another cementitious wall section on aform surface supported thereon and in edge to edge abutting relation toa like wall section previously formed in like manner, and continuing theoperation of thus forming cementitious wall sections until a wall of thedesired dimension is completed.

5. A method of constructing concrete walls, tanks and the like insections disposed in alignment about a common center, which consists inproviding a plurality of forms each having an upright surface facingoutwardly from a common center, projecting cementitious compositionpneumatically onto said surfaces from points spaced outwardly therefromto a depth forming wall sections thereon, moving one of the forms abouta vertical axis at the center to another position after the cementitiouswall thereon has set, projecting another wall section in like mannerthereonto while the wall section previously formed on another of saidsurfaces is setting, and repeating the operation until the desired walldisposed about the center is formed, said surfaces being located in acommon annular plane about said axis during the wall forming operationsthereon.

6. A method of constructing a curved concrete wall in sections about apredetermined center,

which consists in providing a plurality of forms each having anoutwardly facing convex surface curved in a common annular plane aboutsaid center and having an area which is of a height substantially equalto the wall to be formed and of a width equal to a segment thereof,projecting wall-forming cementitious composition pneumatically onto saidsurfaces from a support movable on a track curved about said centerforwardly of and adjacent to the surfaces, moving the forms about thecenter to other positions after walls formed thereon have set, andcontinuing the operation of forming said wall sections by projectingcementitious materialfrom the track support onto the form surfaces movedabout said center until the desired wall is completed.

7. Apparatus for constructing concrete walls, tanks and the like insections disposed about a common center, comprising a segmental framesupporting thereon a form having a form surface extending upwardly froma wall-supporting base to the height of the proposed wall, said surfacefacing outwardly from a predetermined center and being of a widthforming a segment of an annulus around said center, and means anchoringthe frame for movement about said center to different positions whereinit is adapted to support a form thereon with its said surface in theannulus, said surface being adapted to receive wall-forming cementitiouscomposition projected thereonto pneumatically from points spacedoutwardly therefrom.

8. The apparatus defined in claim 7 in which the frame and form have attheir top portion a dome-ring forming contour with an upwardly facingconcrete-receiving surface, and means' whereby the frame and form can beslightly. dropped and shifted radially toward said center to clear aconcrete dome-ring and wall section formed on said upwardly andoutwardly facing surfaces.

9. Apparatus for constructing relatively high vertical walls for tanksand the like in sections about a common center, comprising a relativelytall and segmental form having a concretereceiving surface facingoutwardly from a predetermined vertical axis, a frame having a verticalportionsupporting the form thereon and a substantially horizontalportion extending to and anchoring the frame for adjustment to differentpositions about said axis as a center, and bracing extending rearwardlyand'downwardly from the vertical portion of the frame to the horizontalportion, the frame being adjustable horizontally to different positionsabout the axis as a center.

JOHN M. CROM.

